Radio apparatus



Feb. 11,1936. w SCHAPER 2,030,271

RADIO APPARATUS v Filed March 6, 1933 t i QZZZwAa/M Patented Feb. 11, 1936 UNITED STATES PATENT OFFICE RADIO APPARATUS 111., a corporation of Application March 6,

6 Claims.

My invention relates to a radio unit and more particularly to a multiple condenser of a radio unit.

In recent radio design it has been common I practice to mount a radio. frequency transformer which has both'its primary and secondary windings tuned in a single shielding container with the tuning condensers.

An object of the present invention is to provide a plurality of condensers in such a unit which may be conveniently adjusted to individually vary their capacities.

A further object is to provide a small and compact condenser assembly in which the condenser 5 plates may have substantially the area of a cross section of the shielding container.

Other objects and advantages will appear as the description proceeds.

In accordance with one embodiment of the invention a pair of plate condensers are mounted on opposite sides of a mounting base and adjusting means are provided for individually adjusting the condensers from the same side of the base, the adjusting means also serving to secure the condensers to the base.

A complete understanding of the invention may be had by reference to the following description taken in conjunction with the accompanying drawing in which Fig. 1 is a side elevation partly in section of a unit embodying the invention,

Fig. 2 is an enlarged fragmentary sectional view of the condenser assembly,

I Fig. 3 is a bottom view taken on line 3-3 of Fig. 2,

Fig. 4 is a perspective view of one of the condenser plates,

Fig. 5 is a diagrammatic view of a circuit in which the unit may be used, and

Fig. 6 is a detail view of a strip for securing the assembly in a shielding container.

The coil and condenser unit is mounted on a base I of any suitable insulating material. This base has a central countersunk aperture for receiving a tubular stem 8 which has a collar 5 intermediate its length for seating in the countersunk aperture in the base and an end ll of the stem is crimped over in another countersunk portion of the aperture to securely retain the stem in the base. The stem is internally threaded and a portion of the projecting end of the stem is externally threaded.-

A condenser is mounted on each side of the base. The upper condenser has a condenser plate I 2 Illino 1933. Serial No. 659,710

lying flat against the top of the base and a second condenser plate I3 which is transversely arched. These condenser plates are separated by a sheet of dielectric material I such as mica. The lower condenser also has a condenser plate I4 lying flat against the base and a second condenser plate l5 which is transversely arched. The condenser plates of the lower condenser are separated by a sheet of dielectric material l6.

All of the condenser plates are preferably square and since the plates forming the two condensers are on opposite sides of the base they may be of substantially the same size as the base. This construction makes it possible to use variable condensers having a large range of capacities with a relatively small base.

The base is provided with a'plurality or apertures l1 and lla extending therethrough and arranged in a rectangular pattern around the peripheries of the condenser plates. The outercondenser plates I3 and H are provided with a plurality oi integral strips such as shown at 18 along one side or the plates which serye as terminals for the condensers and also to position the plates. The central or middle strips I8 01' plates l3 and I5 serve as supports for a coil mounting plate I! and preferably extend into notches or cut-out portions 22 in the periphery of the base. The strips I8 of the lower condenser plate l5 may extend upwardly through the apertures 11. and thestrips of the upper condenser-plate I! are provided with portions 2| which are bent downwardly to extend into apertures I I and then upwardly. The condenser plates l2 and I4 are provided with strips Illa which .are disposed in the apertures Ila in a manner similar to that described in connection with strips IS in apertures l1 and one of the strips I 8a of each condenser plate I2 and Il may extend upwardly through the coil mounting plate I! to assist in supporting this plate. It will be evident that the number of strips provided on a condenser plate may be varied to suit any particular need. As long as a condenser plate has two strips engaging apertures in the base, it will be held in position and prevented from rotational movement.

In order to adjust the upper condenser. a headed screw 23 provided with a thread is inserted in the stem 8 and an insulating washer 24 is placed under the head of screw 23 to insulate the screw from the condenser plates. .It will be seen that the apertures in the condenser plates are of such size that the plates do not contact with the screw. The lower end of the screw 23 is provided with a the base.

contact with the stem 8 thus making the upper and lower condensers electrically independent.

, The condenser plates I3 and I5 are preferably duplicates except that some or all of the strips 18 of the plate II are bent back as shown at 2| in Fig. 2.

One vof the outstanding advantages of the above described condenser construction is that the base of the unit maybe made considerably smaller than ina common type of unit in which the condensers are mounted side by side on one side of the base.

For the purpose of mounting coils ii and 82 o! a radio frequency transformer on the base some of the strips l8 are provided with reduced ends 33 which pass through apertures in the plate I! and are bent over. The coils are wound on adowel pin 34 which is supported in an aperture in plate IS. The coils are connected to the condensers as shown diagrammatically in Fig. 5.

A condenser and coil assembly of the type described is usually mounted in a shielding container 36 on a chassis 31. In some cases the coils are mounted above the condensers as illustrated and in other cases the entire assembly is inverted in the container. This invention is applicable to either method. when the assembly is mounted as illustrated the condensers may be adjusted through an opening ll in the chassis, and when the assembly is inverted the condensers may be adjusted through an opening "in the shielding container.

In order to secure the assembly in the container the base I is provided with a pair of resillent arms ll the lower ends oi. which are extend through apertures in the container.

U-shaped' and are clamped over reduced portions 42 in the base. The upper ends of these arms are provided with bent portions 43 which A fine wire may be placed around the outside of the container passing through the projecting portions of the bends to firmly secure the assembly in the container. The arms are of such length and the apertures in the container are so located that the assembly will be in the proper position s,oao,s71

in the container, when the assembly is mounted as illustrated or inverted. I

It will be understood that the embodiment of the invention herein described is merely illustrative and that many changes and modifications may bemade therein withoutdeparting Irom the spirit and scope of the invention.

I claim:

1. In a radio apparatus a mounting base, a condenser mounted on each side of said base, each condenser having a plurality of plates, and a coaxial adjusting means for varying the axial distance between said plates to individually adjust 7 said condensers.

2. In a radio apparatus, a mounting base, a condenser mounted on each side thereof, said condensers comprising a plurality 01' plates, an adjusting member for one of said condensers extending through said base for varying the distance between the, planes of said plates, and a second adjusting member concentric therewith and surrounding the first adjusting member for varying the distance between the planes oi the plates of the second condenser.

3. In a radio apparatus a base; a condenser mounted on each side of the base and supported solely on the base, and means individual to said condensers for adjusting the condensers from one side orthe base, said adjusting means being mounted on the base.

v 4. A condenser unit comprising a base, a tubular stenr mounted therein and projecting therefrom, said stem beingv internally and externally threaded, a condenser mounted on each side oi said base, means engaging the internal threads of the stem for adjusting one of said condensers, and means engaging, the external threads for adjusting the other condenser.

5. A condenser unit comprising a' base, .a condenser mounted on each side of the base, said condensers having a plurality 01' plates, andcoaxial means for individually adjusting the perpendicular distance between the plates of the condensers.

6. A condenser assembly comprising a base, a condenser mounted on each side of the base, said condensers having plates disposed in substantially parallel planes and in superposed relation,

.and coaxial adjusting means for varying the.

axial distance between said plates to individually adiust the capacities of said condensers.

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